Best Yukgaejang - How To Make Yukgaejang: Spicy Korean Beef Soup

Ingredients

• 1 lb. beef brisket
• 1 peeled medium onion, half kept whole and half thinly sliced
• 6 dried or fresh shiitake mushrooms
• 3 tbsp. gochugaru
• 3 tbsp. sesame oil
• 2 tbsp. soy sauce
• 2 tbsp. minced garlic, from about 10 cloves
• 1 tbsp. kosher salt
• 1/2 tsp. freshly ground black pepper
• 1 c. dried gosari, soaked in hot water for 30 minutes and cut into 2-inch pieces
• 1 leek, quartered lengthwise and cut into 2-inch strips
• 6 oz. mung bean sprouts
• 1 c. dangmyeon, soaked in hot water for 30 minutes, optional
• Cooked rice, for serving